Project Title: Metal-Catalyzed C-H Borylation: Design of New Catalysts with New Selectivities Abstract C?H borylation is a synthetic methodology where C?H bonds in an organic molecule react with B?H or B?B bonds forming a B?C bond. It has been widely applied in the functionalization of sp2 C?H bonds, but examples of sp and sp3 C?H bonds have been reported. The products of these reactions are important intermediates, which leverage the remarkable versatility of B?C bonds for installation of other functional groups under mild conditions. In this renewal application, we propose to advance our understanding of C?H borylations and to orthogonally develop the methodology such that it can offer solutions to synthetic problems faced by the biomedical community. Some of the specific aims build on chemistry that was developed in the previous funding cycle, while other specific aims are entirely new. Specifically, we propose to (1) the design of low- coordination number catalysts for directed sp2 and sp3 C?H borylation; (2) The design of ligand frameworks for meta and para C?H borylations; and (3) Hydrogenation of C?H borylated arenes and heterocycles to achieve formal sp3 C?H borylation. We will pursue these aims through a collaborative multi-investigator venture that bring the power of inorganic chemistry and organic synthesis to bear on the problem.